Hydraulic transmission



Feb. 24, 1953 D. E. TRIPP 2,629,332

HYDRAULIC TRANSMISSION Filed Sept. 29, 1947 e Sheets-Sheet 1 E' Tripppwlqh f INVENTO ATTORNEY Feb. 24, 1953 D. E. TRIPP 2,629,332

' HYDRAULIC TRANSMISSION Filed Sept. 29, 1947 6 Sheets-Sheet 2 A TTORNEY Feb. 24, 1953 0'. E. TRIPP 2,629,332

HYDRAULIC TRANSMISSION Filed Sept. 29, 1947 6 Sheets-Sheet 3 Dwight E.Tri

INVENTOR.

ATTORNEY Feb. 24, 1953 D. E. TRIPP 2,629,332

HYDRAULIC TRANSMISSION Filed Sept. 29, 1947 6 Sheets-Sheet 5 I E. TrippINVENTOR.

ATTORNEY Feb. 24, 1953 D. E. TRIPP HYDRAULIC TRANSMISSION 6 Sheets-Sheet6 Filed Sept. 29, 1947 m i hb NWT Q\ WNNW \L QMT Mi ATTORNEY PatentedFeb. 24, 1953 UNITED STATES PATENT OFFICE HYDRAULIC TRANSMISSION,

Dwight E. Tripp, Tyler, Tex., assignor to Tackett & Tripp, Inc., Tyler,Tex.

Application September 29, 1947, Serial No. 776,772

4 Claims.

This invention relates to hydraulic transmis-' sions and it hasparticular reference to such a transmission designed primarily to beused as a power unit for motor vehicles but not necessarily 7 adaptationto a motor vehicle, and the engine R. P. M. The desirable effectproduced by virtue of this governing action under which the transmissionis constantly operated include the ability to gain maximum horsepowerthrough rapid engine acceleration; high cruising ratios and controlledratio increase at predetermined engine speeds.

Another object of the invention is to provide a power transmissiondesigned for high working pressures at low fluid volume per unit with aconsequent saving in power losses. Moreover, due i to continuous anduninterrupted fluid circulation,

r a housing in which operates a driving shaft,

grouped about which is a series of plunger constrained by a cam track toreciprocate under v spring resistance and effective to create chambersin which fluid is entrapped between said plungers and the blades of arotor on said shaft.

Provision is further made of a booster pump actuated by the drivingshaft to insure maximum inlet pressure on the low pressure side of thetransmission and to compensate for any leakage. Also,

. the provision of meansto convey fluid into the operative range of theplungers through the driving shaft from whence the fluid, underincreased A pressure is conveyed through the said drivin shaft to adriven element or elements. A reciprocable ratio control valve isprovided which is actuated through the coordinating action of acentrifugal governor on the driving shaft and the variable pull ofvacuum of the air intake of the engine.

With the foregoingobjects in view, the invention has further referenceto certain features of accomplishment which will become apparent as thedescription proceeds, taken in connection with the accompanying drawingswherein: Figure 1 isa sideelevational view of a trans+ missionconstructed according to the present invention, partly in section,showing forward position of the transmission. p

Figure 2 is a similar view but showing neutral position of the parts. 7

Figure 3 is a view in transverse section taken on line 3--3 on Figure 1.

Figure 4 is a view in transverse section taken on line I--4 on Figure 1.2

Figure 5 is a fragmentary perspective View partly in section and on areduced scale, showing the cam operated plungers of the driving shaft.

Figure 6 is a fragmentary sectional view showing the manually controlledvalve in reverse position.

Figure 7 is a view similar to Figure 6 but showing the control valve inneutral position.

Figure 7A is another view of the valve shown in Figures 6 and 7 showingforward position thereof.

I Figure 8 is a view in transverse section taken on line 88 on Figure l.s

Figure 9 is a fragmentary perspective View, partly in section showinganother position of the cam and plunger assembly as compared to Figure5. I

Figure 10 is a fragmentary view of the driving 2 shaft showing invertical section the reciprocating valve in forward" position.

Figure 11 is a transverse sectional view of the driving shaft, taken online II-II of Figure 10.

Figure 12 is a sectional view taken on line I I2I2 of Figure 10.

Figure 13 is a sectional view taken on line I3.I3 0f Figure 10.

Figure 14 is a sectional view taken on line I l-44 of Figure 10, and i iFigure 15 is a vertical sectional view similarto i FigurelO but showingthe reciprocating valve in reverse position on the driving shaft.

Continuing with a more detailed description of the drawings, referencenumeral I0 denotes the transmission case into which extends a drivingshaft II. The case I8 is sealed against leakage of fluid with which thecase is filled, a packing gland I2 being provided at the point where theI shaft II enters the case.

Surrounding the Shaft u within the case in" is the body I 3 of thetransmission which is a heavy bore I4 of larger diameter than thatthrough which shaft I I ,is passed and is concentric there- An axialbore 2|, larger than the shaft bore but smaller than the bore I4, entersfrom the end of the body I3 and communicates with the end of the boreI4. Grouped about the. bore -2I is a series of small parallel bores 22,in each of which is reciprocably mounted a hollow plunger 23. The innerends of the plungers 23' bear against the end I9 of the sleeve I5, andit will become apparent as the description proceeds that these plungersare reciprocated to move them successively out of 'th'e'p'ath'of theblades 20 as the driving shaft I I is rotated.

Referring again to the sleeve I5, it will be observed in Figures 1 and'2 that pins 24 secured thereto-pass through slots 25 into an annularspace 26 formed about the driving shaft II and tothe inner end of eachpin 24 is threadedly secured a rod 2'! which rods extend forwardlythroughtheboss I8 and their opposite ends are secured to, an annular cam28 and whose reciprocal movement is effected by correspondingreoip'rocal movement o'fthe sleeve I5 through rods 2 I, in a manner tobe later described.

Mo 'nted on each of the reciprocable plungers 23 is a, clamp 29, eachcarrying a pin 30 on which.

is mounteda roller 3|. The rollers 3| operate on and are; controlledbythe undulating. face of the cam. The cam 28 has an integral sleeve 32which surrounds the driving shaft II in the intermediate bore 2| of thebody I3 and on the end of this sleeve is formed an annular flange33'which serves as a retainer for a thrust bearing 34 against whichlattehin turn, bear the ends of coiled springs 35, .in/c'dncentricrelationship. The innr end or the smallest spring engages a ring 35reciprocable on the sleeve 32. This ring 36 carfies,.ro'll'ersfi'lItiiihountedon pins 30a in diametrical opposition to'rollers 3|. Theinner end of the largestspringbars against an annular flange 31,,ftowhich 'itattach'ed the pivots 30 of rollers 3|, to resist reciprocativedisplacement of plungeis 23. It'is apparent from this description thatthe cam 28 is rotatable with the drivingshaft I I, yet the valve liftingassembly including the plungers 23 are constrained against other thanreciprocati've movement.

Theplungers 23 are hollow, as shown, in order thatflth'ey maymove freelyin their respective "bores without building up resistive pressure ateach end. Threaded plugs 38 close the outer ends of the -plunger bores22 and accessibility is had to the clamps 29'of the plun'gers 23 throughradial openings 39 in the body I3.

'The' driving shaft II has an axial fluid inlet passage 40 through whichfluid enters the annular' pressure chamber, indicated in Figures 5 and 8by reference numeral 4|, the same being definedat the end I9 of sleeveI5 and divided into "equal compartments bythe rotor blades 20 (Fig.

5) Theflui'd through the'passage'40is admitted "on the low pressure orinlet side of the'rotor blades 20 through inlet ports 42a whenthe driv-'ing shaft II has rotated to a'position' prepara- "tor'y to displacementof 'plungers 23. Intake of compression is constant in front of the sameex-' cept when load drives the pump, in which case the pressure zonesare reversed.

Fluid is forced from the compression chamber in advance of the blades.28 through a discharge port 42a into a discharge passage 43 in thedriving shaft I I parallel with inlet passage 40. From passage 43,.thefluid enters an annular chamber 44 of a reciprocating valve 5 when thesaid annular chamber 44 is in register with the outlet 46 of saidpassage 43. From the annular chamber 44 of the reciprocating valve 45,the fluid under pressure, flows through pressure line 41 (Fig. 4) to thefluid motors of the vehicle wheels, not shown, on to other drivenelement or elements. After having performed its'work, the fluidreturns'to the reciprocating valve chamber 43 through line 48a and fromwhich it re-enters the return passage 40 by way of inlet port 40a forrecirculation.

The reciprocating sleeve I5 performs the function of varying the fluiddisplacement of the pump, as it operates against the resistance of fluidboth in the pressure chamber 4| and in the annular space I6 at theopposite or rear end of the sleeve. In order to increase the capacity ofthe pump, it is necessary to bleed the annular chamber I6 to increasethe volume of fluid handled. This is accomplished by actuating a ratiocontro1 valve 49 (Figs. 1 and 2)' so that fluid will flow from chamberI6 through passages 50 5|, 52

' and 53, back into 'the fluid reservoir which occupies the spacebetween the case 50 and'body I3. To lower the ratio, it is necessary toopen the annular chamber IE to fluid in the pressure passage This isaccomplished through passage 54 (Fig. 1) into which fluid flows from aflexible tube 55, entering the same through a passage 56 in thereciprocating valve body 45 from the annular chamber 48 thereof througha communicating passage 51, the latter controlled by check valves 58which latter serve'the function to select high pressures for the reasonthat one is open to pressures originating in passage 43 and iseffective' to close the companion valve, by virtue of a communicatingpassage 59.

To operate the ratio control valve 48, a link 60 is connected thereto,as shown in Figures '1 and 2 and the opposite end of thellnk isconnected to an arm 5| intermediate its ends. It will be explainedpresently how this arm is oscillated to impart reciprocal motion to link60 and valve 49, but. in the meantime, it is pointed out that while theratio control valve 49 is supplying pressure to the annular chamber I6through passage 50, a force is exerted on sleeve l5 to the left inFigure 1. This results in similar displacement of a cross-head 62 due toa connection afforded between the valve 49 and cross-head by a rod 63.By virtue of a tongue and groove B4, forming connection between thecross-head 62 and sleeve I5, the latter is permitted to rotate with theshaft II, the cross-head being limited to reciprocative displacement. a

It is apparent from the foregoing that fluid volume in the annularpressure chamber 4| is in direct proportion to thearea of the chamber ITin advance of the sleeve l5 (Fig. 1), that is to say, when the sleeve I5is moved to the left, the

volume of fluid in chamber 4| is decreased and when it is moved to theright, the volumeis increased in chamber 4 I.

The governing means 1 for the transmissionconsists of two coordinatingelements, i. e., a centrifu'gal governor andapistonactuated byvacuum tocorrespondingly move the arm 6i. Bil is attached to the arm Bl, thevalve 49 will be to the instrument panel of the vehicle. 'tionsofForward, Neutral and Reverse are created in the intake manifold of theengine. By virtue of these coordinating elements, it is possible tocontrol the transmission for any desired ef- .fect; The centrifugalgovernor consists of guides .55 radially arranged about the axis of theshaft H in a flywheel 66 mounted on the end of the latter. Slidablyarranged in these guides are weights 5?, to which are attached wirelines 68 operating over pulleys 69. The opposite ends of .these wirelines extend at right angles and are attached to the flange 10 of asleeve H which latter is slidably mounted on the shaft H. A coiledspring 12 interposed between the flange 10 and hub of the flywheel 66resists outward displacement of weights 65 when influenced bycentrifugal force imposed by rotation of shaft ll. Mounted on anextension of the sleeve H is a ball bearing i3 and surrounding the outerrace of this bearing is a collar 14, the latter being pivoted thereto at'15 (Fig. 3) at diametrically opposite points. The ring or collar-14therefore is constrained against other than oscillative displacement onits pivots l5, hence-the arm or arms 6! attached thereto may oscillateas described, on a pivot 76 adjacent the upper end,

actuated to change the relative positions of the fluid passagescontrolled thereby to determine the action of the sleeve {.5 to controlthe volume of fluid entering the pressure chamber 4!, in the 'mannerdescribed. Coordinating with the centrifugal governor just described isa cylinder 18 mounted exteriorhr of the case ill, in which operates apiston 19. Engine manifold suction through flexible line 89 displacesthe piston 19 to exert a pull on link 81, thereby rocking arm 6| on itspivot 76. The eiiect on the arm 6! is similar to its actuation by thecentrifugal governor in the sense that the sleeve I5 is affected throughoperation of the ratio control valve 49. It is through the describedarrangement that the proper ratio between power and load may occur atthe proper time.

Manual control of the transmission is effected through the medium of acable 82 which extends Designaprovided to guide the operator. The cable82 actuates a rotary valve 83 (Figs. 1, 2, 6, '7 and {7A). which, inorder to move the vehicle forward,

is positioned so that its passages 84 will be aligned with passages 85in the body of the reciprocating valve 45.

A clutch valve 86 (Fig. 2) controls the passages 85, through which fluidis introduced at comparatively low pressure of ap- "proximately 100pounds, from a pump 81, through pump discharge line 88 and passage 89.

The clutch valve 85 is actuated by a cable 9!) (Fig. 2), one end ofwhich is attached to a bell crank 95, pivoted at 92. The opposite end ofthe cable 90 is engageable at 93 by the lower end of the arm iii.Therefore, the clutch valve 83 will be actuated by the arm Bl when theengine is speeded up or idled.

Figures 6 and 7 show respectively the reverse and neutralpositions ofthe rotary valve. At

aeeaese the side of this valve opposite the clutch valve 86, thepassages 84 thereof communicate with a cylinder 94 through passages 95and 96 (Fig. 7A). As shown in Figure 2, the clutch valve 86 is inneutral position and the corresponding position of the rotary valve isas shown in Figure '7, although the rotary valve can be in neutral,engine acceleration will not effect engaging of the load until it isplaced in forward or reverse position. In such position, pressure atatmosphere will pass into cylinder 84 on opposite sides of its piston91, through passages 95 and 96. However, in forward position of retaryvalve 83, fluid will enter cylinder 94 through passage 95 while inreverse position thereof, pressure will enter cylinder 94 on theopposite side of piston 9'! through passage 96. A coil spring 98 isarranged in the cylinder 94 on each side of its piston 91 to balance thesame and make it possible to go into neutral when piston is exposed tothe same pressure on both sides.

It will be observed in Figure 2 that the cylinder 94 is mounted on theunderside of the reciprocating valve body 45 and moves therewith whilethe rod of its piston 91 passes into a recess in: the transmission body13 and is stationarilyanchored by means of a pin 99 secured in the bodyit. Accordingly, when pressure is introduced into the cylinder 94through" one or the other of the passages 95 or 96, the cylinder 94 willbe displaced, thereby actuating the reciproeating valve 45. It isobvious that one of the cylinders 94 can be mounted on each side of thereciprocating valve 45 to better balance the same.

When the reciprocating valve is moved by pressure entering cylinder 94as described, it is moved from one extreme to the other on the drivingshaft I! therefore the annular chambers 44 and 48 thereof are alignedalternately with the intake and outlet ports 40a and 46 of the returnand pressure lines 48 and 43 respectively which latter are, as stated,in respective communication with flexible lines 4'! and 48a which leadto and from the driven elements.

In Figure 2 may be seen a group of three check .valves lflilwhich effectcommunication between the inlet line 88 of pump 81 and the return line46. These valves are provided to insure entry of fluid into the lowpressure or intake side of the transmission under any conditions. Theobject for this is to keep all slack out of the intake side of thetransmission and to compensate for leakage.

The pump 81 is driven by means of a worm HJI mounted on the impellershaft I02 of the pump, said worm being engaged with a worm gear I93mounted on the drive shaft H.

The reciprocating valve .5, as shown in Figure 1 is in the forwardposition. When in the position at the extreme right it will be inreverse position but as shown in Figure 2, it is in neutral position.The flow of fluid through passages 49 and 43 is reversed in the extremeright position, and when the annular chambers 44 and 48 are in anintermediate position as in Figure 2 in relation to the intake andoutlet ports of the pressure and return passages MI and 43, the positionis neutral and the fluid will merely circulate in passages 40 and 43with no effect.

In operation, rotation of shaft ll imparts rociprocates the plungers 23in pairs, causing them to successively move out of the path of rotorblades in t ermal. se c am er.- 41. w t

is divide'd into intake and exhaust compartments by these blades andplungers coordinately. In the meantime, fluid enters the inlet or lowpressure compartment of the annular chamber 4| through longitudinalpassage 49 of the drive shaft ll behind the rotor blade whilecompression takes 'place' in the companion compartment forwardly of theblade 20 whence it is expelled under high pressure into passage 43 fromthis passage into the annular chamber 44 of the reciprocating valve 45,thence to the fluid motors of the vehicle wheels through flexible lines41.

Fluid continues to flow to the fluid motors and returnsthrough'flexible' lines 48a 'for recirculation as describedas'longas'the shaft 1 i rotates except when the'manual control cable 82 isactuated to place the transmission in reverse" or neutral position, ineither of which cases, circulation in the passages and 43 remainsunchanged but the changed position ofreciproca'ting valve -45 reversesth-einlet and outlet ports of valve 45 in relation to the inletand'outlet ports of passages 40 and 43.

When cable 82 is moved into reverse position, this has the effect todispose rotary valve 83 in' the position shown in Figure 6, reversingthe passages thereof in relation to fluid passages 85 and passages 95and 9B. Fluid pressure entering cylinder 94 causes the cylinder to moveto the opposite extreme, carrying with it the reciproeating valve 45,thereby bringing into register the ports 48 and 44 thereof with inletand outlet ports of passages 40 and 43 in the manner explained in thepreceding paragraph, whereupon fluid pressure is applied to the wheelfluid motors through flexibleline Mia instead of line 41.

When neutral position obtains, the control valve 83 is disposed as shownin Figure 7, fiuid being cut off from cylinder 94 while springs 98balance the cylinder in its centermost position to similarly dispose thereciprocating'valve 45. In this position of valve 45, its annularchambers 4 4 and 4B are disposed in an intermediate position in relationto the inlet ports of passages 40 and '43 ,'during which fluid willmerely circulate in these passages and will have no effect to drive thefluid motors of the vehicle wheels.

In any case, whether in forward or reverse position, thetransmission isundercon-stant, control of the two governing factors, i. e., vacuum fromthe engine intake andthe centrifugal govern-or, these being in balanceso that the desired efiect or ratio will be predetermined at all times.

Ratio is increased when there isa partial vacuum in cylinder 18' andwhen the engine is accelerated. In any case, the pivoted arm 6| iseffectiveito actuate the ratio control valve 49 to vary the volume offluid entering and leaving the rotor-and to operate theclutch'valve 83which controls fluid passing through the rotary, manually actuated valve83 and consequently the positioning of the reciprocating valve throughcylinder $4 to determine the flow course of fluid from the latter.

Manifestly, the construction as shown and described is capable of somemodification andisuch modification as may be construed to fall withinthe scope and meaning of the appended claimsis also considered to bewithin the spirit and intent having along'itudinal bore, a fluidapportioning sleeve reciprocablymountedfon'saidldriving 'ele- V 8 V ment'in'said bore, an annular boss on said driving element, said body, saidboss and said'sleeve defining an'annular pressure chamber, rotor bladeson said boss'projecting into said pressure cha n ber, the capacity ofsaid pressure chamber varying with the position of said sleeve, aplurality of reciprocable' plungers mounted in longitudinal boresprovided in said body movable into said chamber and cooperating withsaid rotor blades to impose pressure on fluid entering said chamber,said rotor blades and said p'lungers separating said chamber into intakeand exhaust compartments, an annular cam rotatable with said drivingelement 'for actuating said plungers, spring means resisting movement ofsaid plungers,'said driving element having fluid circulating passagesarranged longitudinally therein communicating with an outlet and aninlet of said pump and with said intake and exhaust compartments, meanson said body for varying the position of said sleeve to vary thecapacity of said pressure chamber to vary the displacement of said pump,and means for maintaining hydrostatic balance of fluid pressures ateachend of said plungers, said cam being longitudinally slidable on saiddriving element, and means connecting said cam and said sleeve wherebyreciprocal movement of said sleeve results in simultaneous longitudinalmovement of said cam. i

2. A hydraulic pump including a driving shaft, a stationary bodyembracing said driving shaft and having a longitudinal bore, said boreextending parallel to and concentric with the longitudinal central axisof said driving shaft; a fluid apportioning sleeve mounted on saiddriving element in said bore for reciprocable movement parallel to saidcentral axis; an annular boss on said driving element, said body,saidboss and said sleeve defining an annular pressure chamber; rotorblades on said boss projecting into said pressure chamber, the capacityof. said pressure chamber varying with the position of said sleeve; aplurality of, plungers mounted in longitudinal bores in said body forreciprocable movement parallel to said central axis into said chamber,said rotor blades and said plungers separating said chamber into intakeand exhaust compartments, said plungers cooperating with said rotorblades to'impose pressure on fiuid enteringsaid chamber; a cam disposedin a plane perpendicular to said central axis and rotatable with'saiddriving element for actuating said plungers to positions without saidchamber and spring means biasing said plungers toward said chambers,said driving element having circulating passages arranged longitudinallytherein, communicating Withan outlet and an inlet of said pump and withsaid intake and exhaust compartments.

3. A hydraulic pump including a driving shaft, a stationary bodyembracing said driving shaft and having a'longitudinal bore, said boreextendsure chamber, the capacity of said pressure chamber varying withthe position of said sleeve; a plurality of plungers mounted inlongitudinal bores in said body for reciprocable movement parallel tosaidcentral axis into said chamber, said 'plung'ers "cooperating'Witlfsaid rotor blades to impose pressure on fluid entering saidchamber, said blades and plungers separating said chamher into intakeand exhaust compartments; a cam disposed in a plane perpendicular tosaid central axis and rotatable with said driving element for actuatingsaid plungers to positions without said chamber, spring means biasingsaid plungers toward said chambers, said driving element havingcirculating passages arranged longitudinally therein, communicating withan outlet and an inlet of said pump and with said intake and exhaustcompartments; said cam being longitudinally slidable on said drivingelement; means connecting said cam and said sleeve whereby reciprocalmovement of said sleeve results in simultaneous longitudinal movement ofsaid cam; and means for moving said sleeve to vary the capacity of saidchamber to vary the displacement of said pump.

4. A hydraulic pump including a driving shaft, a stationary bodyembracing said driving shaft and having a longitudinal bore,said boreextending parallel to and concentric with the longitudina1 central axisof said driving shaft; a fluid apportioning sleeve mounted on saiddriving element in said bore for reciprocable movement parallel to saidcentral axis; an annular boss on said driving element, said body, saidboss and said sleeve defining an annular pressure chamber; rotor bladeson said boss projecting into said pressure chamber, the capacity of saidpressure chamber varying with the position of said sleeve; a pluralityof plungers mounted in longitudinal bores in said body for reciprocablemovement parallel to said central axis into said chamber, said plungerscooperating with said rotor blades to impose pressure on fluid enteringsaid chamber, said blades and plungers separating said chamber intointake and exhaust compartments;

, fining a second chamber remote from said plungers; and valve means forselectively connecting said second chamber to one of said longitudinalbores whereby fluid under pressure may be admitted into said secondchamber to move said sleeve toward said plungers to decrease the disacam disposed in a plane perpendicular to said central axis and rotatablewith said driving element for actuating said plungers to positionsplacement of said pump and for selectively connecting said secondchamber to an outlet whereby fluid may escape from said second chamberto permit said sleeve to move away from said plungers to increase thedisplacement of said pump.

DWIGHT E. TRIPP.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,008,202 Schmucker Nov. 7, 19111,156,816 Rich Oct. 12, 1915 1,246,322 Richer et al Nov. 13, 19171,276,372 Johnson Aug. 20, 1918 1,532,735 Dickerson 1 Apr. 7, 19251,797,905 Dooley Mar. 24, 1931 1,954,793 Averin Apr. 17, 1934 2,190,122Mohler Feb. 131, 1940 FOREIGN PATENTS Number Country Date 6,431 GreatBritain Mar. 14, 1911

